Peterson : Description of Stenomylus. 



293 



comparatively a slightly less transverse diameter than in the former 

 genus. The pisiform is in its outline almost identical with that of 

 Lama huanaco, but slightly longer in proportion. In Oxydactylus, 

 this bone has a longer shaft and does not have the oblique postero- 

 inferior face of the free end seen in the 

 present genus, but is more cubical in out- 

 line. 



In view of the general modification of 

 the fore limb, which seems to be slightly 

 more advanced than in Oxydactylus and 

 perhaps the Miocene camels generally, it 

 is surprising to find a trapezium of nearly 

 the same proportions as in Oxydactylus 

 longipes. The trapezium of the present 

 genus is an oblong nodule resembling a 

 sesamoid. The anterior face is entirely 

 taken up by a large articular facet for the 

 trapezoid, which is at right angles with a 

 smaller facet for the scale-like mc. II on 

 the distal face of the bone. The trape- 

 zoid is in its proportions and outlines more 

 nearly like that in Oxydactylus than in L. 

 huanaco. The facet for the trapezium is 

 of the same relative size as in the former 

 and the convex articular surface for the 

 scaphoid meets the latter facet at an open 

 angle on the posterior face of the trape- 

 zoid. The magnum possesses a relatively 

 greater antero-posterior diameter than in 

 Lama huanaco, which is chiefly due to the 

 relatively larger palmar hook in the present 

 genus. This hook is much compressed 

 laterally and the articulation for the third 

 metacarpal extends well back on its distal 

 face quite like that in Oxydactylus. The 

 unciform is comparatively narrow and 

 deep ; its palmar hook, though proportionately somewhat lighter than 

 in Oxydactylus, is, nevertheless, similar to it. The bone as a whole is 

 more nearly like that in Oxydactylus than in the recent forms. The 



Fig. 8. Anterior and radial 

 views of fore foot of Steno- 

 mylus gracilis. Type No. 

 1610. 

 pezium. 



nat. size, tin, tra- 



